Devices for maintaining the shapes of shirt collars in storage are known. A typical approach seems to be to slide a partial or full supporting band or similar member underneath the collar, and to optionally lock it in place with a tab engaging the collar points at the throat, sometimes in conjunction with stays. Examples are shown in U.S. Pub No. 2013/0269078; U.S. Pat. Nos. 5,769,287; 4,133,463; 6,889,387 (Tiss et al.), U.S. Pat. No. 2,518,300 (Fine, Sr.); and U.S. Pat. No. 2,275,098 (Welch).
U.S. Pat. No. 2,053,564 to Knopp teaches a shirt collar protector with an inner band located against the inside face of the collar band, and a rear flap that folds over and underneath the rear of the collar to hold the inner band in place. The front ends of the inner band can be secured together at a notch in one end.
It is believed that the prior art does not teach a protector that is convenient to apply and that both protects and supports the entirety of the collar in storage, even when the shirt is stored with items pressing on top of it, for example when packed in a suitcase.